Episode premise:
Kivas Fajo is determined to add the unique Data to his prized collection of one-of-a-kind artefacts and, staging Data’s apparent death, he imprisons him aboard his ship.
We know that Data is later logically coerced to lie in “Clues” to protect the crew, but this appears to be a decision all his own. Or did he not in fact actually fire the weapon?
Yup exactly. He just lacked emotional subroutines (at first) and the hardware to process that. But he doesn’t need emotions to kill. He is in fact capable of using lethal force (First Contact), he just has an ethical subroutine that prevents killing (Descent I, II) unless in defense of others, himself, or The Federation. Which would fall under his logical subroutines.
Similar in a way to Chief Engineer Hemmer who will not use violence (Memento Mori) unless in an act of preserving life. The means to defend is part of the training of a Starfleet officer.